D7e 48a converting from pony to electric start.

I'd recommend you replace the existing ring gear and go with the ready to install starter conversion as shown. Just be sure you order with the RH helical drive gear.
Otherwise it takes a 24v 50MT starter, clockwise rotation, a special adapter drive end housing and 11 tooth RH helical drive gear.
Also need to check that the attachment mounting holes are tapped as not all of them are.
http://www.ebay.com/itm/NEW-50MT-PONY-MOTOR-REPLACEMENT-STARTER-24VOLT-24V-FITS-CATERPILLAR-D7-D8-D9-/110922514286?hash=item19d37f3f6e:g:lJEAAOSwvgdW2czY&vxp=mtr

I'd recommend you replace the existing ring gear and go with the ready to install starter conversion as shown. Just be sure you order with the RH helical drive gear.
Otherwise it takes a 24v 50MT starter, clockwise rotation, a special adapter drive end housing and 11 tooth RH helical drive gear.
Also need to check that the attachment mounting holes are tapped as not all of them are.
http://www.ebay.com/itm/NEW-50MT-PONY-MOTOR-REPLACEMENT-STARTER-24VOLT-24V-FITS-CATERPILLAR-D7-D8-D9-/110922514286?hash=item19d37f3f6e:g:lJEAAOSwvgdW2czY&vxp=mtr

OM, wouldn't he be better off since he has to change the ring gear anyway to go back with straight cut and get the matching starter? I always thought the starter engaged and disengaged cleaner with straight cut gears. Also eliminates any starter drive confusion.

That is an option but my parts book shows a different flywheel assembly for the straight cut gear. I'm not convinced they interchange or that you can just interchange the ring gear. Also the starter required takes the long nose drive end housing and special adapter if you go straight cut. With those unknowns I'd go with the conversion. Engagement is not an issue.

Thanks for the info OM. I think I'll try to source a ring OE ring gear and go with the starter you suggested. Do those slight helix starter/ring gears ever act up or act up faster then straight cut?

Not a problem that I am aware of. Might be a little harder on the older inertia drive starters but that's not what your are dealing with. I'd say thousands of tractors have been converted with no where near the problems of the pony drive pinions and ring gear mesh.

Either way you will be happy with the conversion, I've done 2 D8H's one with the original ring gear, one was chewed up like yours so went with the straight cut. Warm up the gear with a rose bud and drop on the flywheel. Nice to eliminate all those moving parts of the starting engine.

Did you check or know for sure that you are getting full starter drive engagement with the straight cut ring gear that was substituted for the original beveled gear?

Did you check or know for sure that you are getting full starter drive engagement with the straight cut ring gear that was substituted for the original beveled gear?